UNCLASSIFIED ADMINISTRATIVE INFORMATION The work reported is a by-product of gross gamma measurements of certain samp!es made for Project 2,5a, Operation CASTLE. It was done unde r Bureau of Ships Proj ect No. NS 088-001, Subtask ll, Technica l Objective SR-2, DD Form 613 of é4 May 1955, and NS 081-001, Subt ask 4, Technical Objective AW-7 , DD Form 613 of 6 October 1955, iv UNCLASSIFIED